Index: llvm-3.3/cmake/modules/GetHostTriple.cmake
===================================================================
--- llvm-3.3.orig/cmake/modules/GetHostTriple.cmake
+++ llvm-3.3/cmake/modules/GetHostTriple.cmake
@@ -15,15 +15,19 @@ function( get_host_triple var )
       set( value "i686-pc-mingw32" )
     endif()
   else( MSVC )
-    set(config_guess ${LLVM_MAIN_SRC_DIR}/autoconf/config.guess)
-    execute_process(COMMAND sh ${config_guess}
-      RESULT_VARIABLE TT_RV
-      OUTPUT_VARIABLE TT_OUT
-      OUTPUT_STRIP_TRAILING_WHITESPACE)
-    if( NOT TT_RV EQUAL 0 )
-      message(FATAL_ERROR "Failed to execute ${config_guess}")
-    endif( NOT TT_RV EQUAL 0 )
-    set( value ${TT_OUT} )
+    if( NOT LLVM_HOST_TRIPLE )
+        set(config_guess ${LLVM_MAIN_SRC_DIR}/autoconf/config.guess)
+        execute_process(COMMAND sh ${config_guess}
+            RESULT_VARIABLE TT_RV
+            OUTPUT_VARIABLE TT_OUT
+            OUTPUT_STRIP_TRAILING_WHITESPACE)
+        if( NOT TT_RV EQUAL 0 )
+            message(FATAL_ERROR "Failed to execute ${config_guess}")
+        endif( NOT TT_RV EQUAL 0 )
+        set( value ${TT_OUT} )
+    else( LLVM_HOST_TRIPLE )
+        set( value ${LLVM_HOST_TRIPLE} )
+    endif( NOT LLVM_HOST_TRIPLE )
   endif( MSVC )
   set( ${var} ${value} PARENT_SCOPE )
   message(STATUS "Target triple: ${value}")